A minesweeper is a military ship designed to locate and destroy naval mines placed in the sea by enemies. The same ships are sometimes used for mine laying.

Onboard, these vessels include specialised sonar and radar to detect and track mines. To avoid detonation of mines, they are designed to produce much less noise than other ships, and are often constructed with hulls of wood, plastic or low-magnetic steel.

Alternately, minesweepers are equipped with powerful electromagnetic degaussing fields to neutralise their magnetic field and/or jammers.

There is a blurred distinction between a minesweeper and a minehunter. A minesweeper is generally designed to clear an area of a large number of relatively simple mines - for example towing a wire sweep to cut loose floating contact mines or a floating cable energised with powerful electric current pulses to detonate magnetic mines. A minehunter is a ship which is better equipped to handle more modern mines which need to be individually located on the sea bed and destroyed. Both kinds of ships are sometimes collectively called MCMVs - mine counter-measure vessels.

Helicopters towing underwater cables are sometimes used for minesweeping.

Their weaponry is mostly designed for the destruction of mines (specialized mortars and short-range torpedoes), but as they are military ships, anti-aircraft and other combative weapons are usually present.